1. Field of Invention
The present invention relates to an antenna structure, and more particularly to an antenna structure that can be attached onto a ceiling, a wall, or a partition wall.
2. Related Art
Antennas are provided for emitting and receiving electric waves, and based on operating bands, antennas can be classified into ultra-long wave, long wave, medium wave, short wave, ultra-short wave, and microwave antennas from low frequency to high frequency. The antennas have been widely applied in military and civilian communication. The sizes and lengths of antennas are quite different according to different operating bandwidths and wave lengths, and antennas can also be classified into omni-directional antennas and directional antennas.
Referring to FIGS. 1 and 2, a conventional antenna structure is shown. An antenna 10 includes a ground plate 12, a signal wire 14, a conductive plate 16, and an insulating sleeve 18. The ground plate 12 is provided for electrical grounding the antenna 10, wherein the grounding plate 12 include a plate portion 122 and a hollow conical dome portion 124 raised on the plate portion 122. The conductive plate 16 and the ground plate 12 are both made of metal, and the conductive plate 16 is electrically connected to a front end the signal wire 14. The insulating sleeve 18 is slip onto the signal wire 14 and clamped between the ground plate 12 and the conductive plate 16, so as to prevent the contact of these two metal plates.
The signal wire 14 includes an extending section 142 extended from an edge of the conical dome portion 124 of the ground plate 12. Then, the extending section 142 is connected to a cable connector 144 fixed on the plate portion 122, such that the signal wire 14 is connected to a cable through the cable connector 144 and then connected to a signal source. Additionally, a seal cap 126 is mounted on the bottom surface of the plate 122 of the antenna and correspondingly under the conical dome 124. A bolt 20 passes through the central portion of the seal cap 126, so that the antenna 10 can be fixed on a ceiling or a wall with the bolt 20.
Based on the above description, the antenna 10 when being installed or used can be connected to the signal source through the cable connector 18, and the bolt 20 and the nut 22 are used together to fix the antenna onto a wall or ceiling. However, it is troublesome to install the antenna structure in two procedures, and besides that, it is also complex to manufacture and assemble the antenna structure as the antenna has a lot of parts.